1. Field of the Invention
The present invention relates to a piezoelectric member, an acoustic wave apparatus, and a piezoelectric member manufacturing method.
2. Description of the Related Art
These days, an acoustic wave apparatus is widely used as, for example, a filter of a mobile communication terminal. It is desired for the acoustic wave apparatus to increase the sound speed of the acoustic wave in order to achieve downsizing, etc. Japanese Patent Laid-Open No. 8-310900 discloses a member with a surface layer made of AlN, for example. Since AlN has a high Young's modulus, using the member disclosed in Japanese Patent Laid-Open No. 8-310900 can increase the sound speed of the acoustic wave apparatus.
However, there is a case where the member disclosed in Japanese Patent Laid-Open No. 8-310900 cannot meet the demand of further increasing the sound speed of the acoustic wave apparatus. That is, although the sound speed of the acoustic wave can be increased to some extent because the surface layer has a high Young's modulus due to being formed of AlN, the member cannot achieve still higher sound speeds sufficiently.